The long term objective of this research is to improve functional treatment outcomes for patients with peripheral arterial disease (PAD) by evaluating lower extremity function and quality of life after surgical revascularization. PAD is a manifestation of systemic atherosclerosis that significantly reduces blood flow to the lower extremities. PAD prevalence ranges from 12-20% in general medical practices with an exponential rise in individuals over 70 years of age. Reduced blood flow leads to pain during walking known as claudication. Claudication results in considerable functional limitations in patients with PAD, primarily related to limb dysfunction. The mechanisms underlying ambulatory limb dysfunction in PAD patients have recently begun to be elucidated with advanced biomechanical analysis. This research has demonstrated the primary limb dysfunction of the PAD patient is significantly reduced ankle plantarflexor power. However, how revascularization affects limb dysfunction of PAD patients is currently unknown. We hypothesize that PAD is a process in the lower extremities resulting in significant limb dysfunction definable by advanced biomechanical analysis. We also hypothesize that gait abnormalities are potentially reversible utilizing current endovascular and open surgical revascularization therapy, leading to restoration of limb function. Our Specific Aims are going to: SPECIFIC AIM 1: Establish baseline limb dysfunction of the patient with isolated femoropopliteal PAD. Patients with unilateral femoropopliteal arterial disease will undergo testing compared to matched healthy control subjects. SPECIFIC AIM 2: Determine the reversibility of the baseline gait deficit. Claudicating patients from Aim 1 will be evaluated at baseline, and at three, six, an 12 months post revascularization. SPECIFIC AIM 3: Determine the benefit of open versus endovascular revascularization. Claudicating patients from Aim 1 will be randomized to open versus endovascular revascularization to determine optimal surgical revascularization. Forty patients with unilateral femoropopliteal arterial disease and 40 healthy age matched controls will be recruited for Aim 1 of the study. Calf skeletal muscle evaluation will be performed using computerized tomography. Lower extremity hemodynamics will be captured through the Ankle/Brachial Index and the ischemic window. Lower extremity function will include advanced biomechanical analysis, spatial and temporal gait parameters, and initial and absolute claudication distances. Quality of life will be determined using the Walking Impairment Questionnaire and the Medical Outcomes Study Short Form 36 Healthy Survey. We expect that claudicating patients will have definable and predictable limb dysfunction as identified by advanced biomechanical analysis and as compared to healthy controls. Claudicating patients from Aim 1 will be randomized to open versus endovascular revascularization and evaluated at three, six, and 12 months post revascularization. It is hypothesized in Aim 2 that revascularization will result in significant improvement in lower extremity hemodynamics and limb function. Aim 3 will determine if open or endovascular revascularization results in greater improvements in limb function. We expect that endovascular revascularization will result in greater improvement in lower extremity function than open revascularization. The proposed project will therefore establish the ability of increased blood flow to reverse gait dysfunction an determine the more effective invasive revascularization strategy for the PAD patient.